Tensile mechanical property testing tool and testing method for flat plate target plate connecting interface

Abstract

The application provides a flat target plate connecting interface tensile mechanical property test tool and a test method, and belongs to the field of nuclear fusion technology. The test tool comprises a clamping assembly, a sample, a centering rod and an adapter. The clamping assembly, the centering rod and the adapter are symmetrically arranged in pairs, and the sample has a symmetric structure. The clamping assembly is symmetrically clamped at both ends of the sample. One end of the centering rod is connected with the clamping assembly, and the other end of the centering rod is connected with the adapter. The adapter is used for being connected with a mechanical tensile tester, so that tensile loading and strength testing are realized. The clamping assembly comprises a clamp block and a clamp cover. The clamp block and the clamp cover are detachably connected through bolts. The clamp block and the clamp cover form a clamping cavity which is matched with the end of the sample. The application effectively relieves the stress concentration problem of the sample shoulder, can prepare multiple samples in a single target plate, more completely evaluates the target plate connecting quality, and realizes automatic centering in the tensile process.

Description

Technical Field

[0001] This invention belongs to the field of nuclear fusion technology, specifically relating to the tensile mechanical properties testing fixture and method for the interface of a flat target plate. Background Technology

[0002] Magnetic confinement fusion energy, as one of the ideal energy sources of the future, places stringent requirements on divertor target plates, requiring a steady-state ultra-high heat load of 20 MW / m². The divertor is a key component of a tokamak device, primarily used to remove impurity particles and helium ash from the fusion reactor and to remove the heat generated by the high-temperature plasma. The divertor target plate consists of plasma-facing materials, heat sink materials, and structural materials, with a typical structure being a multi-layered flat plate configuration of tungsten / copper alloy / structural steel. The tungsten / copper alloy layers are often joined using hot isostatic diffusion welding or brazing, while the copper alloy / structural steel layers are joined using hot isostatic diffusion welding or explosive welding. Therefore, accurately testing the tensile strength, fracture toughness, and other mechanical parameters of the target plate's interface is crucial for the structural design and process optimization of the divertor target plate, as well as for assessing the degradation of its mechanical properties under actual operating conditions.

[0003] In conventional tensile mechanical property testing, standard wedge clamps are widely used for tensile testing of metals and composite materials due to their self-tightening clamping function. They achieve horizontal closure of the clamping surfaces through clamp body movement, allowing for specimen clamping without applying additional compressive force. While existing technologies can meet the tensile testing requirements of conventional ductile metals, they present the following technical problems when testing the tensile mechanical properties of flat target plate connection interfaces: 1) Pure tungsten is a typical brittle material. The concentrated radial clamping stress generated by the wedge clamp easily leads to breakage at the tungsten-side clamping end, causing the specimen to fracture at the clamping end rather than the connection interface, making it impossible to obtain true interface strength data; 2) The tungsten armor layer thickness of prototype components is typically only 4-5 mm. To ensure the test interface is located at the center of the specimen gauge length, the available length of the tungsten-side clamping end is strictly limited, failing to meet the minimum clamping length requirement of the wedge clamp. This results in existing flat target plate connection interface testing methods only being able to test simplified planar joints, lacking a complete mechanical property testing method for flat divertor targets. Summary of the Invention

[0004] This invention provides a testing fixture and method for testing the tensile mechanical properties of the connection interface of a flat target plate, which solves the problems that existing testing methods for the connection interface of flat target plates can only test simplified planar joints and cannot simulate real complex structures. Furthermore, traditional testing methods cannot be applied due to size limitations and the fragility of tungsten side materials.

[0005] To achieve the above objectives, the present invention provides a tensile mechanical property testing fixture for a flat target plate connection interface. This fixture includes a clamping assembly, a specimen, a centering rod, and an adapter. The clamping assembly, centering rod, and adapter are arranged in pairs and symmetrically, and the specimen has a symmetrical structure. The clamping assembly symmetrically clamps both ends of the specimen. One end of the centering rod is connected to the clamping assembly, and the other end is connected to the adapter. The adapter is used to connect with a mechanical tensile testing instrument to achieve tensile loading and strength testing. The clamping assembly includes a clamp block and a clamp cover, which are detachably connected by bolts. The clamp block and clamp cover together form a clamping cavity adapted to the end of the specimen.

[0006] Accordingly, the present invention also provides a testing method for a tensile mechanical property testing fixture for a flat target plate connection interface, used in the tensile mechanical property testing fixture for a flat target plate connection interface described above. The testing method includes the following steps: Step S1, sampling from the test area of ​​the target plate and processing it into the required contour, machining positioning holes at both ends of the sample, and polishing the sample to complete the sample pretreatment; Step S2, placing the sample into the clamping cavity of the clamping assembly, positioning it by inserting small pins into the positioning holes, locking the clamp cover, and connecting the centering rod to the clamping block to complete the sample clamping; Step S3, fixing the adapter to the loading seat of the mechanical tensile testing instrument, engaging the top end of the centering rod with the adapter to form a movable centering fit, and completing the fixture assembly; Step S4, starting the mechanical tensile testing instrument to perform tensile testing, calculating the tensile strength parameters based on the collected maximum tensile force value and the effective force-bearing area of ​​the sample connection interface to complete the performance test.

[0007] The beneficial effects of this invention are as follows:

[0008] This invention optimizes the design of the tensile specimen structure, avoiding the increasingly squeezed effect caused by directly clamping the specimen, and provides a tensile fixture and testing method suitable for multi-layer dissimilar metal samples. The specimen transmits force collaboratively with the shoulder of the fixture via a small pin, effectively alleviating stress concentration at the specimen shoulder, preventing tungsten fracture, and providing positioning. The fixture design significantly reduces the length of the specimen clamping end, ensuring the testing interface is centered on the specimen gauge length. The miniaturized specimen design also allows for the preparation of multiple specimens from a single target plate, enabling a more complete evaluation of the target plate connection quality and facilitating high-temperature and fusion irradiation tests. The semi-circular centering structure simplifies the assembly process, limits the relative oscillation of the specimen at small angles, and enables automatic centering during tensile testing. Attached Figure Description

[0009] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0010] Figure 1 This is a schematic diagram of the test fixture assembly provided in an embodiment of the present invention;

[0011] Figure 2 This is an exploded view of the test fixture provided in an embodiment of the present invention;

[0012] Figure 3 This is a structural diagram of the clamping assembly for removing the clamp cover provided in an embodiment of the present invention;

[0013] Figure 4 This is a structural diagram of the clamp block provided in an embodiment of the present invention;

[0014] Figure 5 This is a cross-sectional view of the divertor target plate provided in an embodiment of the present invention;

[0015] Figure 6 This is a schematic diagram of sample taking for a divertor target plate provided in an embodiment of the present invention;

[0016] Figure 7 This is a structural diagram of the sample provided in the embodiments of the present invention;

[0017] Figure 8 This is a sample size diagram for testing the W / ODS-Cu bonding surface provided in an embodiment of the present invention;

[0018] Figure 9 This is a sample size diagram for testing the W / ODS-Cu / RAMF steel connection surface provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures:

[0020] 10. Clamping assembly; 11. Clamping block; 12. Bolt; 13. Clamping cover; 14. Small pin; 15. Buffer pad; 16. Limiting pin; 20. Specimen; 21. Specimen for W / ODS-Cu connection surface; 22. Specimen for W / ODS-Cu / RAMF steel connection surface; 30. Centering rod; 40. Adapter; 51. Heat dissipation fins; 52. Tungsten layer; 53. Oxygen-free copper transition layer; 54. ODS-Cu layer; 55. RAFM steel layer; 111. Center threaded hole; 112. Clamping cavity; 113. Cylindrical hole; 201. Inclined surface; 202. Shoulder arc transition surface; 203. Tension section; 204. Positioning hole. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above objectives, this invention adopts the following technical solution.

[0022] To better characterize the mechanical properties of the joint interface between flat target plates, this invention aims to propose a testing fixture and method for the tensile mechanical properties of the joint interface between flat target plates. This provides an applicable tensile testing and experimental method for the research and manufacturing of dissimilar material welding of tungsten / copper alloy / structural steel.

[0023] Figure 1 This is a schematic diagram of the test fixture assembly provided in an embodiment of the present invention. Figure 2 This is an exploded view of the test fixture provided in an embodiment of the present invention. Figure 3 This is a structural diagram of the clamping assembly for removing the clamp cover provided in an embodiment of the present invention. Figures 1 to 3 This is a landscape view. Figures 1 to 3 The left and right sides correspond to the upper and lower parts of the actual structure, respectively. Below, we will combine... Figures 1 to 3 The present invention will be described in detail.

[0024] On the one hand, the present invention proposes a mechanical performance testing fixture for the target plate connection interface of a divertor flat plate structure. The fixture includes a clamping assembly 10, a sample 20, a centering rod 30 and an adapter 40. The clamping assembly 10, the adapter 40 and the centering rod 30 are all arranged in pairs and symmetrically, and the sample 20 has a symmetrical structure.

[0025] The clamping assembly 10 is symmetrically clamped at both ends of the specimen 20. One end of the centering rod 30 is connected to the clamping assembly 10, and the other end is connected to the adapter 40. The adapter 40 is used to dock with the mechanical tensile testing instrument to realize tensile loading and strength testing.

[0026] The clamping assembly 10 includes a clamping block 11 and a clamping cover 13. The clamping block 11 and the clamping cover 13 are detachably connected by bolts 12. The clamping block 11 and the clamping cover 13 together form a clamping cavity 112 that is adapted to the end of the specimen 20. The clamping end face of the specimen 20 and the tensile section 203 are rounded to form a shoulder arc transition surface 202. An inclined surface 201 is machined along the shoulder arc transition surface 202. The specimen 20 fits into the clamping cavity 112 and is in contact with the inner wall surface of the clamping block 11. Two symmetrical positioning holes 204 are provided at each of the two ends of the specimen 20. Figure 7 This is a structural diagram of the sample provided in the embodiments of the present invention, such as... Figure 7As shown. Small pins 14 are inserted into the clamping assembly 10 and the sample 20 to achieve stress dispersion and positioning of the sample 20. The sample 20 is a composite plate cut from a divertor target plate. The divertor target plate is welded from three layers of materials: tungsten, copper alloy, and structural steel. In this invention, a target plate composed of tungsten (W), oxide dispersion strengthened copper (ODS-Cu), and low-activation martensitic steel (RAFM steel) is used as an example. The welding of the tungsten layer 52 and the ODS-Cu layer 54 uses an oxygen-free copper transition layer 53 as a transition layer. The ODS-Cu layer 54 is provided with heat dissipation fins 51, and the thickness of the tungsten layer 52 is 5-8 mm.

[0027] Two clamping blocks 11 are symmetrically arranged and clamp the two ends of the specimen 20. The groove shape inside the two clamping blocks 11 at the corresponding positions on the specimen 20 is the same as that of the specimen 20, but the depth is slightly greater than the thickness of the specimen 20. A corresponding number of cylindrical grooves are opened on the side of the clamping block 11 that is in parallel contact with the specimen 20. Small pins 14 are inserted into the cylindrical grooves of the two symmetrical clamping blocks 11 to share the tensile stress, relieve the stress concentration at the shoulder of the specimen, and achieve positioning.

[0028] The clamp block 11 has two cylindrical holes 113 at one end, and the limiting pin 16 passes through the pair of clamp blocks 11 to limit the rotation and radial movement of the clamp block 11 during the stretching process.

[0029] Figure 4 This is a structural diagram of the clamp block provided in an embodiment of the present invention, as shown below. Figure 4 As shown, each clamping block 11 has two cylindrical holes 113 at one end, so that the limiting pin 16 passes through the two cylindrical holes 113 of each clamping block 11 and is inserted between the paired clamping blocks 11, thereby restricting all rotation and radial movement of the clamping blocks 11 during the stretching process. The other end of the clamping block 11 has a central threaded hole 111.

[0030] A buffer pad 15 is provided between both ends of the sample 20 and the clamp cover 13 to ensure that the clamp cover 13 and the sample 20 are tightly fitted and fixed. Specifically, the clamp cover 13 covers the outside of the clamp block 11, and the clamp cover 13 and the clamp block 11 are locked and fixed by bolts 12. The buffer pad 15 is placed between both ends of the sample 20 and the clamp cover 13 to ensure that the clamp cover 13 and the sample 20 are tightly fitted and fixed to prevent the clamp from loosening. There are also cylindrical grooves on the inner side of the clamp cover 13 corresponding to the number of grooves in the clamp block 11. Small pins 14 pass through the clamp block 11, the sample 20, the buffer pad 15 and the clamp cover 13 in sequence to complete the fixation.

[0031] Furthermore, the two centering rods 30 are symmetrically arranged. For each centering rod 30, one end of the centering rod 30 is provided with an external thread, which is fastened to the central threaded hole 111 of the clamp cover 13. There are two symmetrical milled planes on the body of the centering rod 30. The height of the centering rod 30 relative to the clamp block 11 can be adjusted by rotating the milled planes with a wrench. The other end of the centering rod 30 is provided with a semi-arc surface structure. A rectangular through groove is opened on one side of the adapter 40, and a semi-arc groove is opened at the lower end of the rectangular through groove to cooperate with the centering rod 30. The top end of the centering rod 30 is laterally inserted into the adapter 40.

[0032] Furthermore, the two adapters 40 are symmetrically arranged vertically. One end of each adapter 40 has a single-sided rectangular through slot, and the lower surface of the rectangular slot has a concave arc surface that matches the semi-circular arc structure of the centering rod 30. The semi-circular end of the centering rod 30 is laterally engaged into the slot of the adapter 40, forming a movable fit that allows for small-angle relative swinging and automatic centering during tensile testing. The other end of the adapter 40 is used to connect with mechanical tensile testing equipment such as an electronic universal testing machine.

[0033] Furthermore, the clamping assembly 10 is made of high-temperature alloy material, which is suitable for high-temperature tensile testing environments.

[0034] During assembly, first insert the limiting pin 16 into the upper and lower symmetrical clamp blocks 11, adjust the distance between the two clamp blocks 11, put the sample 20 into the clamping cavity 112, align the positioning hole 204, insert the small pin 14 into the corresponding cylindrical groove of the sample 20 and the clamp block 11 and put in the buffer pad 15, and use the bolt 12 to lock the clamp cover 13 and the clamp block 11; then screw the threaded sections of the two pairs of center rods 30 into the clamp blocks 11 at the upper and lower ends respectively.

[0035] The two adapters 40 are fixedly connected to the upper and lower loading seats of the electronic universal testing machine, respectively. Then, the lower end of the lower centering rod 30 is engaged with the lower adapter 40. Finally, a wrench is used to rotate the upper centering rod 30 to adjust the height of the top of the upper centering rod 30 relative to the upper adapter 40 to a suitable position, and they are engaged to form a movable centering fit, thus completing the tooling assembly.

[0036] During testing, the tensile load is transmitted to the clamping assembly 10 via the adapter 40 and the centering rod 30. The force is transmitted in coordination with the side shoulder of the clamp through the small pin 14, stabilizing the mechanical properties of the connection interface of the test specimen 20.

[0037] Figure 5 This is a cross-sectional view of the divertor target plate provided in an embodiment of the present invention, such as... Figure 5As shown, the divertor target plate is welded from three layers: a tungsten layer 52, an ODS-Cu layer 54, and a RAFM steel layer 55. Because the connection between the tungsten layer 52 and the ODS-Cu layer 54 is difficult, an oxygen-free copper transition layer 53 is used as the transition layer. The W / ODS-Cu layer is typically connected using hot isostatic diffusion welding or brazing, while the ODS-Cu / RAFM steel layer is connected using hot isostatic diffusion welding or explosive welding. The ODS-Cu layer 54 is equipped with heat dissipation fins 51, and the tungsten layer 52 has a thickness of 5 mm.

[0038] On the other hand, the present invention proposes a testing method for a testing fixture for the tensile mechanical properties of a flat target plate connection interface, used to test the tensile mechanical properties of the flat target plate connection interface provided by the present invention. The testing method includes the following steps:

[0039] Step S1: Take a sample from the area to be tested on the target plate and process it into the required contour. Machining positioning holes 204 at both ends of the sample 20 and polishing the sample 20 to complete the sample pretreatment.

[0040] In step S1, the uniformity of the target plate joint is evaluated using ultrasonic non-destructive testing. Sampling is performed uniformly, avoiding welding defect areas and edge heat-affected zones. The target plate is then cut into the required pieces using a slow wire EDM / low-speed diamond band saw on the area to be tested. Subsequently, the sample is machined to the contour for tensile testing using a precision grinder. Four 1.2mm diameter through holes are then machined / drilled on the ground sample using electrical discharge machining (EDM) to complete the sample processing. The end faces, sides, and cut edges are then polished to remove burrs and oxide layers. Finally, laser marking and key dimension verification are performed on the sample to complete the sample pretreatment.

[0041] Step S2: Place the sample 20 into the clamping cavity 112 of the clamping assembly 10, and position it by inserting the small pin 14 into the positioning hole 204. Then lock the clamp cover 13, connect the centering rod 30 to the clamp block 11, and complete the clamping of the sample 20.

[0042] In step S2, the limiting pin 16 is inserted into the upper and lower symmetrical clamp blocks 11, the distance between the two clamp blocks 11 is adjusted, the sample 20 is placed into the clamping cavity 112, the small pin 14 is inserted into the positioning hole 204 of the sample 20 and the corresponding cylindrical groove of the clamp block 11, and the buffer pad 15 is put in. The clamp cover 13 and the clamp block 11 are locked with bolts 12, and the threaded sections of the two centering rods 30 are screwed into the clamp blocks 11 at the upper and lower ends respectively to complete the clamping of the sample 20.

[0043] Step S3: Fix the adapter 40 to the loading seat of the mechanical tensile testing instrument, and engage the top end of the centering rod 30 with the adapter 40 to form a movable centering fit, thus completing the tooling assembly.

[0044] In step S3, the two adapters 40 are fixedly connected to the upper and lower loading seats of the mechanical tensile testing instrument, respectively; then the lower end of the lower centering rod 30 is engaged with the lower adapter 40; finally, a wrench is used to rotate the milled plane of the upper centering rod 30 to adjust the height of the top of the upper centering rod 30 relative to the upper adapter 40 to a suitable position, and they are engaged to form a movable centering fit, thus completing the tooling assembly.

[0045] Step S4: Start the mechanical tensile testing instrument to perform tensile testing. Based on the collected maximum tensile force value and the effective force-bearing area of ​​the connection interface of the specimen 20, calculate the tensile strength parameters to complete the performance test.

[0046] In step S4, based on the maximum tensile force value collected by the mechanical tensile tester and combined with the effective force-bearing area of ​​the connection interface of the sample 20, the tensile strength, elongation at break, and other mechanical property parameters of the divertor target plate connection interface are calculated.

[0047] During testing, the tensile load is transmitted to the clamping assembly 10 via the adapter 40 and the centering rod 30. The force is then transmitted in coordination with the side shoulder of the clamp block 11 through the small pin 14 to stabilize the mechanical properties of the connection interface of the test specimen 20.

[0048] In the design specifications for divertor targets, the interfacial bonding strength of each metal layer in sample 20 must be greater than or equal to the strength of the weaker base material. However, in actual tensile fracture processes, fracture can be divided into two main categories: fracture occurring at the joint interface and fracture in the base material far from the joint interface.

[0049] If the fracture occurs along the joint interface or within the heat-affected zone extending 0.5 mm from the joint interface to both sides of the base material, such a test can measure the bonding strength of the weaker joint interface and determine that the test piece does not meet the design requirements and requires further optimization of the welding process; if the fracture occurs in the base material far from the joint interface, then the test measures the lower limit of the bonding strength of the weaker joint interface.

[0050] The testing method provided by the present invention also includes a high-temperature environment adaptation step: the entire testing fixture is placed in a high-temperature heating chamber, heated to 200-700℃ at a rate of 5℃ / min, and kept at that temperature for 30 minutes to make the sample temperature uniform before performing a tensile test; the buffer pad 15 is replaced with a high-temperature nickel-based alloy material to press the sample 20 tightly against the clamp block 11 and prevent high temperature.

[0051] In one embodiment, a high-temperature tensile testing method is provided at the W / ODS-Cu interface using the above-described testing fixture.

[0052] In this embodiment, the W / ODS-Cu bonding surface uses sample 21 (such as...). Figure 6The composite plate shown is cut from the divertor target plate and is made of two layers of materials, tungsten layer 52 and ODS-Cu layer 54, welded together. Since it is difficult to connect tungsten layer 52 and ODS-Cu layer 54, oxygen-free copper transition layer 53 is used as the transition layer.

[0053] The following is in conjunction with the appendix Figure 8 The W / ODS-Cu bonding surface sample 21 of the present invention will be described in detail. Figure 8 This is a sample size diagram for testing the W / ODS-Cu connection surface provided in an embodiment of the present invention. The clamping end face of the W / ODS-Cu connection surface sample 21 is rounded to form a shoulder arc transition surface 202 between the clamping end face and the tensile section 203. An inclined surface 201 is processed along the shoulder arc transition surface 202. The total length of the W / ODS-Cu connection surface sample 21 is a1=12mm, the total width is b1=6mm, the clamping end length is c1=2mm, and the sample thickness is t1=1mm. The rounded end face of the clamping end face and the tensile section 203 is rounded to form a shoulder arc transition surface 202. An inclined surface 201 is processed along the shoulder arc transition surface 202. The radius of the rounded corner of the shoulder arc transition surface is R1=1.5mm, the angle between the two inclined surfaces is θ1=150°, the diameter of the positioning hole is d1=1.2mm, the horizontal center distance of the positioning holes is g1=9.4mm, and the vertical center distance of the positioning holes is f1=3mm. The width of the tensile section is e1=1.8mm.

[0054] For testing the W / ODS-Cu interface, samples can be taken from the internal heat dissipation fins 51 of the flat target plate or from the side surface of the flat target plate. In this example, sample 21 is taken from the W / ODS-Cu interface on the internal heat dissipation fins 51 of the flat target plate. Figure 6 As shown, the divertor plate target is a multi-layer composite structure. The uniformity of the target plate joint is evaluated by ultrasonic non-destructive testing. A flat area on the target plate without macroscopic defects and deformation is selected as the sampling area.

[0055] First, a sampling groove is machined on the target plate. Material from the inner heat dissipation fin 51 is taken and cut into the required pieces on the test area of ​​the target plate using a slow wire EDM / low-speed diamond band saw. Then, the sample is machined to the contour of the tensile test using a precision grinder. Next, four 1.2mm diameter through holes are machined / drilled on the ground sample using electrical discharge machining. During the sampling process, it is necessary to ensure that the W / ODS-Cu interface structure of the target plate is completely preserved by the sample 21 without processing damage. After the sample is cut, its end face, side face and cutting edge are polished to remove burrs and oxide layer, resulting in a test sample with a smooth and defect-free surface.

[0056] The sample clamping is then performed. First, the limiting pin 16 is inserted into the upper and lower symmetrical clamp blocks 11. The distance between the two clamp blocks 11 is adjusted. The W / ODS-Cu connecting surface sample 21 is placed into the clamping cavity 112 and aligned with the positioning hole. The small pin 14 is inserted into the corresponding hole of the W / ODS-Cu connecting surface sample 21 and the clamp block 11, and the buffer pad 15 is inserted. The clamp cover 13 and the clamp block 11 are locked with bolts 12. Then, the threaded sections of the two pairs of center rods 30 are screwed into the clamp blocks 11 at the upper and lower ends respectively to complete the sample clamping.

[0057] The two adapters 40 are fixedly connected to the upper and lower loading seats of the electronic universal testing machine, respectively. Then, the lower end of the lower centering rod 30 is engaged with the lower adapter 40. Finally, a wrench is used to rotate the upper centering rod 30 to adjust the height of the top of the upper centering rod 30 relative to the upper adapter 40 to a suitable position, and they are engaged to form a movable centering fit, thus completing the tooling assembly.

[0058] The entire test fixture is placed in a high-temperature heating chamber and heated to 200-700℃ at a rate of 5℃ / min, and held at that temperature for 30 minutes to ensure uniform sample temperature before tensile testing. The buffer pad 15 is replaced with a high-temperature nickel-based alloy material to press the sample tightly against the fixture and prevent high temperature.

[0059] Finally, based on the maximum tensile force value collected by the testing machine, and combined with the effective stress area of ​​the W / ODS-Cu joint interface using specimen 21, the bonding strength of the W / ODS-Cu joint interface can be obtained if the fracture occurs along the joint interface or within the heat-affected zone extending 0.5 mm from the joint interface to both sides of the base material. If the fracture occurs in the base material far from the joint interface, then the test yields the lower limit of the bonding strength of the W / ODS-Cu joint interface.

[0060] In one embodiment, a room-temperature tensile testing method is provided for the W / ODS-Cu / RAMF steel interface using the above-described test fixture.

[0061] Sample 20 can be a composite plate sampled from a divertor target plate, which is welded from a tungsten layer 52, a copper alloy layer, and a structural steel layer. For testing the tungsten / copper alloy interface, samples are taken from the heat dissipation fins 51 inside the flat target plate or from the side surface of the flat target plate. For testing the tungsten / copper alloy / structural steel interface, samples are taken from the side surface of the flat target plate. The copper alloy in the copper alloy layer can be, for example, oxide dispersion strengthened copper (ODS-Cu), and the structural steel in the structural steel layer can be, for example, low-activation martensitic steel (RAFM steel).

[0062] In this embodiment, sample 22 (e.g., W / ODS-Cu / RAMF steel joint surface) is used. Figure 6The composite plate shown is cut from the divertor target plate and is made of three layers of materials: tungsten layer 52, ODS-Cu layer 54, and RAFM steel layer 55. The welding of tungsten layer 52 and ODS-Cu layer 54 uses oxygen-free copper transition layer 53 as a transition layer.

[0063] The following is in conjunction with the appendix Figure 9 The W / ODS-Cu / RAMF steel joint surface specimen of the present invention will be described in detail. Figure 9 This is a sample dimension diagram for testing the W / ODS-Cu / RAMF steel connecting surface provided in this embodiment of the invention. The clamping end face of the W / ODS-Cu / RAMF steel connecting surface sample 22 is rounded to form a shoulder arc transition surface 202 between the tensile section 203 and the clamping end face. An inclined surface 201 is machined along the shoulder arc transition surface 202. The total length of the W / ODS-Cu / RAMF steel connecting surface sample 22 is a2 = 25 mm, the total width is b2 = 6 mm, and the clamping end length is c2 = 2mm, sample thickness t2=1mm; the chamfered corner between the clamping end face and the tensile section 203 forms a shoulder arc transition surface 202, along which an inclined surface 201 is machined, the radius of the shoulder arc transition surface radius R2=1.5mm, the angle between the two inclined surfaces θ2=150°; the positioning hole diameter d2=1.2mm, the transverse center distance of the positioning holes g2=22.4mm, the vertical center distance of the positioning holes f2=3mm; the width of the tensile section e2=1.8mm. For the testing of the W / ODS-Cu / RAMF steel interface, sampling is selected from the side surface of the flat target plate. Combined with Figure 6 As shown, Figure 6 This is a schematic diagram of sample taking for a divertor target plate provided in an embodiment of the present invention. The divertor flat target plate has a multi-layer composite structure. The uniformity of the target plate joint is evaluated by ultrasonic non-destructive testing. A flat area on the target plate without macroscopic defects and deformation is selected as the sampling area.

[0064] First, a sampling groove is machined on the target plate. Material is taken from the side surface and cut into the required pieces on the target plate's test area using a slow wire EDM / low-speed diamond band saw. Then, the sample is machined to the tensile test profile using a precision grinder. Finally, four 1.2mm diameter through holes are machined / drilled on the ground sample using electrical discharge machining. During the sampling process, the W / ODS-Cu / RAMF steel interface structure of the target plate must be completely preserved using sample 22, without any machining damage. After the sample is cut, its end face, side face, and cut edges are ground and polished to remove burrs and oxide layers, resulting in a smooth, defect-free test sample.

[0065] Then, the test clamping is carried out. First, the limiting pin 16 is inserted into the upper and lower symmetrical clamp blocks 11. The distance between the two clamp blocks 11 is adjusted. The W / ODS-Cu / RAMF steel connecting surface sample 22 is placed into the clamping cavity 112 and aligned with the positioning hole 204. The small pin 14 is inserted into the corresponding hole of the W / ODS-Cu / RAMF steel connecting surface sample 22 and the clamp block 11 and the buffer pad 15 is put in. The clamp cover 13 and the clamp block 11 are locked with bolts 12. Then, the threaded sections of the two pairs of center rods 30 are screwed into the clamp blocks 11 at the upper and lower ends respectively to complete the sample clamping.

[0066] The two adapters 40 are fixedly connected to the upper and lower loading seats of the electronic universal testing machine, respectively. Then, the lower end of the lower centering rod 30 is engaged with the lower adapter 40. Finally, a wrench is used to rotate the upper centering rod 30 to adjust the height of the top of the upper centering rod 30 relative to the upper adapter 40 to a suitable position, and they are engaged to form a movable centering fit, thus completing the tooling assembly.

[0067] Finally, based on the maximum tensile force value collected by the testing machine, and combined with the effective stress area of ​​the interface of the W / ODS-Cu / RAMF steel joint surface using specimen 22, if the fracture occurs along the joint interface or within the heat-affected zone extending 0.5 mm to both sides of the base material centered on the joint interface, the bonding strength of the weaker joint interface in the divertor target plates W / ODS-Cu and ODS-Cu / RAMF can be obtained; if the fracture occurs in the base material far from the joint interface, then the test measures the lower limit of the bonding strength of the weaker joint interface.

[0068] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. The present invention is not limited to changes in sample size and sampling location. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0069] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0070] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0071] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. A tooling for testing the tensile mechanical properties of a flat target plate connection interface, characterized in that, The test fixture includes a clamping assembly (10), a sample (20), a centering rod (30), and an adapter (40). The clamping assembly (10), the centering rod (30), and the adapter (40) are all paired and symmetrically arranged, and the sample (20) has a symmetrical structure. The clamping assembly (10) is symmetrically clamped at both ends of the sample (20). One end of the centering rod (30) is connected to the clamping assembly (10), and the other end of the centering rod (30) is connected to the adapter (40). The adapter (40) is used to dock with the mechanical tensile testing instrument to realize tensile loading and strength testing. The clamping assembly (10) includes a clamping block (11) and a clamping cover (13). The clamping block (11) and the clamping cover (13) are detachably connected by bolts (12). The clamping block (11) and the clamping cover (13) together form a clamping cavity (112) that is adapted to the end of the sample (20).

2. The tensile mechanical property testing fixture for the interface of a flat target plate as described in claim 1, characterized in that, The clamping end face of the specimen (20) and the stretching section (203) are rounded to form a shoulder arc transition surface (202). An inclined surface (201) is processed along the shoulder arc transition surface (202). The specimen (20) fits into the clamping cavity (112) and is in contact with the inner wall of the clamping block (11). Two symmetrical positioning holes (204) are opened at each end of the specimen (20). Small pins (14) are inserted into the clamping assembly (10) and the specimen (20) to achieve stress dispersion and positioning of the specimen (20).

3. The tensile mechanical property testing fixture for the connection interface of a flat target plate according to claim 2, characterized in that, The sample (20) is a composite plate made by wire cutting from a divertor target plate. The divertor target plate is mainly made of three layers of materials: tungsten, copper alloy, and structural steel.

4. The tensile mechanical property testing fixture for the connection interface of a flat target plate according to claim 3, characterized in that, The clamp block (11) has two cylindrical holes (113) at one end, and the limiting pin (16) passes through the pair of clamp blocks (11) to restrict the rotation and radial movement of the clamp block (11) during the stretching process.

5. The tensile mechanical property testing fixture for the connection interface of a flat target plate according to claim 4, characterized in that, A buffer pad (15) is provided between the two ends of the sample (20) and the clamp cover (13) to make the clamp cover (13) and the sample (20) fit tightly and fix together.

6. The tensile mechanical property testing fixture for the interface of a flat target plate according to claim 5, characterized in that, Two centering rods (30) are symmetrically arranged. For each centering rod (30), one end of the centering rod (30) is provided with an external thread, which is fastened to the central threaded hole (111) of the clamp cover (13). There are two symmetrical milled planes on the body of the centering rod (30). The other end of the centering rod (30) is provided with a semi-arc surface structure. A rectangular through groove is opened on one side of the adapter (40). A semi-arc groove is opened at the lower end of the rectangular through groove to cooperate with the centering rod (30) and the top of the centering rod (30) is laterally inserted into the adapter.

7. The tensile mechanical property testing fixture for the interface of a flat target plate according to claim 6, characterized in that, The clamping assembly (10) is made of high-temperature alloy material and is suitable for high-temperature tensile testing environment.

8. A testing method for a tensile mechanical property testing fixture for a flat target plate connection interface, used in the tensile mechanical property testing fixture for a flat target plate connection interface as described in claim 7, characterized in that, The testing method includes the following steps: Step S1: Take a sample from the target plate to be tested and process it into the required contour. Machining positioning holes (204) at both ends of the sample (20) and polishing the sample (20) to complete the sample pretreatment. Step S2: Place the sample (20) into the clamping cavity (112) of the clamping assembly (10), and position it by inserting the small pin (14) into the positioning hole (204). Lock the clamp cover (13), connect the centering rod (30) to the clamp block (11), and complete the clamping of the sample (20). Step S3: Fix the adapter (40) to the loading seat of the mechanical tensile tester, and engage the top of the centering rod (30) with the adapter (40) to form a movable centering fit and complete the tooling assembly. Step S4: Start the mechanical tensile testing instrument to perform tensile testing. Based on the maximum tensile force value collected and the effective force-bearing area of ​​the connection interface of the sample (20), calculate the tensile strength parameters to complete the performance test.

9. The testing method for the tensile mechanical properties testing fixture of the flat target plate connection interface according to claim 8, characterized in that, The sample (20) is a composite plate sampled from a divertor target plate, which is welded from a tungsten layer, a copper alloy layer and a structural steel layer; for the test of the tungsten / copper alloy interface, the sample is taken from the heat dissipation fins (51) inside the flat target plate or from the side surface of the flat target plate; for the test of the tungsten / copper alloy / structural steel interface, the sample is taken from the side surface of the flat target plate.

10. The testing method for the tensile mechanical properties testing fixture of the flat target plate connection interface according to claim 9, characterized in that, The test method also includes a high temperature environment adaptation step: the test fixture is placed in a high temperature heating box and heated to 200-700℃ at a rate of 5℃ / min, and kept at that temperature for 30 minutes to make the sample temperature uniform before performing a tensile test; the buffer pad (15) is replaced with a high temperature nickel-based alloy material to press the sample (20) against the clamp block (11) and prevent high temperature.

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